Thin flexible radio frequency identification tags and subsystems thereof

• US 7,642,918 B2
• Filed: 10/20/2006
• Issued: 01/05/2010
• Est. Priority Date: 10/21/2005
• Status: Expired due to Fees

• Current Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Durgin, Gregory D., Kippelen, Bernard
• Primary Examiner(s): Pham; Toan N
• Assistant Examiner(s): MCNALLY, KERRI L
• Application Number:
  US11/584,086
• Publication Number:
  US 20070103311A1
• Time in Patent Office: 1,173 Days
• Field of Search: 340/572.8, 340/572.1, 340/10.1
• US Class Current: 340/572.8
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card

Abstract

Embodiments according to the present invention comprised RFID tags comprised of components disposed on a flexible conformal substrate. The substrate may be substantially transparent or opaque and the components may be comprised of organic electronic components. Components and circuits may be manufactured using thin-film deposition processes or by deposition of metal-containing inks using inkjet technology. Exemplary use of an embodiment according to the present invention is as a component in an on-vehicle radio-frequency (RF) automated toll system.

Claims

1. A radio frequency identification (RFID) transponder comprised of:

a substantially flexible, conformal substrate whereupon is disposed one or more electronic devices comprising;

an antenna;

a power source, wherein said power source comprises an organic photovoltaic cell, an RF charge pump comprised of SiGe or GaAs semiconductor diodes, a battery, and a voltage regulator;

a modulator comprising a crystalline diode bonded to organic circuitry; and

a data/identification memory unit,

wherein said electronic devices are operatively coupled using one or more conductive circuits disposed upon said flexible, conformal substrate, and wherein said RFID transponder is operable at frequencies between 2.35 and 2.55 GHz.

2. The RFID transponder of claim 1, wherein said antenna comprises a half-wave, folded dipole antenna.

3. The RFID transponder of claim 2, wherein said half-wave folded dipole antenna is designed for resonance at a frequency greater than or equal to 900 megahertz (MHz).

4. The RFID transponder of claim 3, wherein said half-wave folded dipole antenna is designed for resonance at a frequency between 2.35 and 2.55 GHz.

5. The RFID transponder of claim 4, wherein said half-wave folded dipole antenna is designed for resonance at a frequency of 2.45 GHz.

6. The RFID transponder of claim 1, wherein said antenna is comprised of an electrically-conductive material deposited on the substrate.

7. The RFID transponder of claim 6, wherein said conductive material is indium-tin oxide deposited on the substrate.

8. The RFID transponder of claim 6, wherein said conductive material is a thin-film metallic material deposited on the substrate by an electroless deposition process.

9. The RFID transponder of claim 8, wherein said thin-film metallic material is selected from a group consisting of thin-film copper material and thin-film silver material.

10. The RFID transponder of claim 6, wherein said conductive material is a conductive ink deposited on the substrate by an inkjet process.

11. The RFID transponder of claim 6, wherein said substrate is at least in part optically transparent.

12. The RFID transponder of claim 6, wherein said substrate is comprised of material selected from a group consisting of polyethylene teraphthalate (PET), polyimide, poly-ethylene naphthalate (PEN), and liquid crystal polymers (LCP).

13. The RFID transponder of claim 11, wherein said antenna is comprised of indium tin oxide (ITO) deposited on the substrate such that said antenna is at least in part optically transparent.

14. The RFID transponder of claim 1, wherein said flexible substrate is comprised of one or more of polyethylene teraphthalate (PET), polyimide, poly-ethylene naphthalate (PEN), or liquid crystal polymers (LCP).

15. The RFID transponder of claim 1, wherein said antenna is comprised of indium tin oxide (ITO) deposited on the substrate comprised of polyethylene teraphthalate (PET) such that said antenna is at least in part optically transparent.

16. The RFID transponder of claim 1, wherein the substrate is comprised of flexible polyethylene teraphthalate (PET) and said antenna is comprised of thin-film metallic material deposited by electroless deposition process on the substrate.

17. The RFID transponder of claim 16, wherein said thin-film metallic material is selected from the group consisting of thin-film copper material and thin-film silver material.

18. The RFID transponder of claim 1, wherein the substrate is comprised of flexible polyethylene teraphthalate (PET) and said antenna is comprised of a conductive ink deposited by an inkjet process on the substrate.

19. The RFID transponder of claim 1, wherein one or more of said modulator, power source or data/identification memory unit are disposed onto said substrate and said one or more conductive circuits by flip-chip application wherein said flip-chip application comprises one or more conductive bumps at least partially in contact with said one or more of said modulator, power source or data/identification memory unit and said one or more conductive circuits and said one or more of said modulator, power source or data/identification memory unit are at least partially covered with an epoxy resin.

20. The RFID transponder of claim 1, wherein said battery comprises a rechargeable battery.

21. The RFID transponder of claim 1, wherein said modulator comprises a positive-intrinsic-negative (PIN) diode.

22. The RFID transponder of claim 21, wherein said PIN diode comprises a crystalline silicon PIN diode.

23. The RFID transponder of claim 21, wherein said PIN diode is disposed onto said substrate and said one or more conductive circuits by flip-chip application comprising one or more conductive bumps at least partially in contact with said one or more conductive elements of said PIN diode and said PIN diode is at least partially covered with an epoxy resin.

24. The RFID transponder of claim 1, wherein said RFID transponder is used on vehicles in an on-vehicle radio-frequency (RF) automated toll system.

25. The RFID transponder of claim 1, wherein said substrate is at least in part optically transparent.

26. The RFID transponder of claim 25, wherein said modulator comprises a positive-intrinsic-negative (PIN) diode.

27. The RFID transponder of claim 25, wherein said RFID transponder is used on vehicles in an on-vehicle radio-frequency (RF) automated toll system.

28. A radio frequency identification (RFID) transponder comprised of:

a flexible polyethylene teraphthalate (PET) substrate whereupon is disposed one or more electronic devices comprising;

a half-wave, folded dipole antenna comprised of indium tin oxide (ITO) deposited on the flexible PET substrate;

a power source, wherein said power source comprises an organic photovoltaic cell, an RF charge pump comprised of SiGe or GaAs semiconductor diodes, a rechargeable battery, and a voltage regulator;

a modulator comprising a crystalline diode bonded to organic circuitry; and

a data/identification memory unit,

wherein said electronic devices are operatively coupled using one or more conductive circuits disposed upon said flexible (PET) substrate.

29. The RFID transponder of claim 28, wherein said half-wave, folded dipole antenna comprises said half-wave, folded dipole antenna having a resonant frequency of greater than or equal to 900 megahertz (MHz).

30. The RFID transponder of claim 28, wherein said half-wave, folded dipole antenna comprises said half-wave, folded dipole antenna having a resonant frequency of between 2.35 and 2.55 GHz.

31. The RFID transponder of claim 29, wherein said half-wave, folded dipole antenna comprises said half-wave, folded dipole antenna having a resonant frequency of 2.45 gigahertz (GHz).